* ATLANTIC TC GENESIS INDEX * * GFS VERSION * * AL902021 09/28/21 06 UTC * TIME (hr) 0 6 12 18 24 36 48 60 72 84 96 108 120 Prob of Genesis 85% 90% LAT (deg N) 6.1 5.8 5.7 6.2 7.3 8.0 8.4 8.6 9.3 10.3 12.3 14.2 16.0 LON (deg W) 18.6 19.5 21.7 21.2 20.5 23.2 25.7 27.3 29.2 31.3 33.0 35.2 36.7 DTL (km) 651 744 900 823 678 841 1060 1215 1391 1578 1697 1905 2061 TRACK SOURCE AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 AP03 TCGI 0-48h Genesis Forecast: 85% is 2.8 times the sample mean ( 30%) TCGI 0-120h Genesis Forecast: 90% is 2.1 times the sample mean ( 43%) --------------------------------------------------------------------------------------------- INDIVIDUAL PREDICTOR CONTRIBUTIONS TO PROBABILITY OF GENESIS ******* 48-HR ****** ******* 120-HR ****** AVG TCGI CONT AVG TCGI CONT DIVERGENCE -1.0 -8.6 30.3% 1.0 -4.0 26.0% VORTICITY 1.7 2.8 17.0% 1.4 2.6 25.3% VERTICAL SHEAR 16.3 10.6 25.6% 18.4 8.3 26.2% RH 73.1 80.4 -0.2% 70.9 78.9 3.3% GOES 29.1 51.9 3.6% 29.3 51.9 2.0% DVORAK 0.8 1.0 8.9% 0.8 1.0 7.0% --------------------------------------------------------------------------------------------- PREDICTOR DEFINITIONS (Averaged Over 500 km Radius) GENESIS CLIM = Climatological Prob (%) of Genesis (Source: NHC-TAFB Invest Database) DIVERGENCE = GFS 850 hPa Horizontal Divergence (x10-7 s-1) VORTICITY = GFS 850 hPa Vorticity (x10-6 s-1) VERTICAL SHEAR = GFS 200-850 hPa Vertical Shear (kt) RH = GFS 600-850 hPa Relative Humidity (%) GOES = GOES Water Vapor Pixels Colder than -40C (%) DVORAK = Dvorak T-number, source: TAFB Version 3.0, July 2018